Apparatus for the depolymerization of hydrocarbons



Nov. 10, 1931. MERCIER 1,831,185

APPARATUS FOR THE DEPOLYMERIZATION OF HYDROCARBONS Filed D90. 13. 1928 2 Sheets-Sheet l F'gA Jean \emuar INVENTQR;

Attorney.

J. MERCIER Nov. 10, 1931.

APPARATUS FOR THE DEPOLYMERIZATION OF HYDROCARBONS Filed Dec. 13. 1928 2 Sheets-Sheet 2 1 Fig.3

Jean Marci U INVENTOR;

Attorney.

rmad Nov. 10, 1931 1,331,135-

UNITED STATES PATaNToF wE l .imn'ltnncimorrmarmcn Application Med December 13, 1928, Serial 80.825324, and. in France December 88, 1887.

The present invention relates to an imunit E through the pipe 17 may be sent into v proved plant for the depolymerization of hyone or more follow ng expans on unlts 1n drocarbons which are in the liquid state, or -.wh1ch further fractional selections are efwhich may be converted into liquids or gases. fected, after which is disposed a condensing The principal features of the said plant tower; said latter vapours may also be sent 55 of the Grille type.

I =w1ll be specified in the following description. directly into the con ensing tower, in which I In the'appended drawings, which is given the last sorting takes place. The unconb way f exam 1 densable gases are. clrculated throughscrub-' Fi re 1 is a iagrammatic vertical section here and purifiers. i of a epolymerization plant, according to the According an embod ment of the mveninvention, showing only the heating unit and tlon, the heating umt B ,(EOIISISCS of a set of. one of the expansion and cooling units. elementary retorts I, earned by the frame2 Figure 2 is a vertical section of a modificaof the furnace, Said retorts 1 are supertion of an expansion and cooling unit, 210- posed, and their longitudinal. axes are ,m-

cording to the invention, which comprises a clined from the horizontal; they ma have u t f ti l Fi ld t b any suitable cross section, and chic y rec- Figure 3 is a diagrammatic vertical section tangular (the longv ax s of the section being of another modificatlbnof the expansion and V rti al) whlchglves to the retort the sha e cooling unit, which comprises a; set of tubes f a beam of high resistance, while the a sorbed heat is more efiiciently d1str1buted. Figure 4- is a perspective view of a modi- Coupling members 3 connect the several -fied construction showing another disposiretorts 111 Such manner as to from the ti f th t t intake of the vapours at 4, to then outlet at In the-apparatus shown in Fig. 1, the hy- QH HS retort of great lengthand 25 drocarbons hi h i t f raw or id l comparatively reduced bulk,ch1efly in height. p hydrocarbons, such as fuel oil or heavy oils n, the couplmg members maybe I 3 i from coal, peat, naphtha, schist, lignite or the i posed at the outside of the frame. 2. In

like, are vaporized by heating in a boiler A, this case y are P p y heat insulated r I of any suitable construction, or in any suitfIQm the atmosphere Plevenhcooling l l 3 able vaporizer. The boiler may be an ordithe P nary boiler, a tubular boiler'or a coiled tube The retorts hm fill d with metallic scale b il or anyother suitable catalyst 1, adapted to- The hydrocarbon may 'also be vaporized b flsslst depolymelization of the y "4 the lower retorts of the unit B supplied wit h e lower elementary retorts, m y hydrocarbon .in the liquid state provided said 3011mm 8 p y g ns sllch as a 1:

retorts are heated to a sufiicient temperature. Film-absorbing Substance; 0 v In the unit B, which'will be further a A the top part of e f a 1s dlsposed scribed, the hydrocarbon vapours are depolym 6 for hot gas at a .sultahle tempera-1 i d and Said vapours a then passed ture, supplied for instance by a fore-hearth I v ,through a regulating chamber 0 aJud a cow and circulating downwardly.- vBellies .7 are duit D leading to the upper part of he first 1 g $33 3 t expanding and cooling unit E, which will be 1 p f o mn 2 :1

I further described. ongi u ma axis an coun ercurren oe v45 The condensed heavy oils 'are delivered $353,352? of the hydrocarbon vapours" h hf of the 5 expahsloh and circulated around the boiler A or any other h and y h returned to h recipient or boiler to-be'heated, so as to re-'v porxzer A [or otherwise used; the unc0n cover the sensible heat of said gases. densed vapours of 011 or petrol (gasoline), A regulating chamber C is preferably disl "in which are also delivered from the ottom of posed at .the top of the heating unit. Into 100 at 8, the burnt gases may be the lower part of said chamber opens a conduit 9 which leadsirong thenppermost retort to the pizg'satdhamber, at a point remote fronfthecondilit 1) connecting said chamber with'the first expansion and cool- 7 ing unit E. Said chamber, which is also filled with metallic scale or other catalyst, need notbe heated. If necessary, the part 10 of the heating unit between said chamber and 10 the uppermost retort may be heat insulated.

T The operation A return conduit 10a leading back to the still or vaporizer A may be 'charge of the liquids, densed'.

provided for the diswhich may have conof the plant is as follows:

. The hydrocarbon vapours entering the bottom of the heating unit at a temperature from T; of naphtha so retorts,

1 overheating,

The depolymerization of the hydrocarbons 80 in the elementary retorts,

will thus take place very slowly; the metallic scale or like catalyst 1 may in certain cases be disposed in such manner as to leave a freespace 1 adjacent the upper generators so that the lightest i and hottest vapours will rise very readily and rapidly whilst the heavy vapours will re main for a longer time inthe lower part of the retorts, in close contact with the catalyst.

The etficiency of the apparatus may be 1non the upper clogged up,

provides,

creased in some cases by a heat insulation 1 portions of the retorts, so that the heating will only take place at the lower and lateral portions of the retorts, thus afacting the heaviest and coldest vapours,

whose depolymerization is thus furthered.

This depolymerization is continued in the regulating chamber C, in which the heaviest and coldest vapours have a tendency to remain while expelling the lighter vapours.

Such a retort, in which the counterflow circulation secures an efficient transfer of heat has the advantage 'ofproviding a natural draught, allowing the lighter and hotter substances to issue more rapidlyirom the cycle than the heavier and colder substances, which cannot be properly attained with horizontal retorts. It is superior to the vertical retor-ts by the fact that it is readily accessible and for a given height a greater length of retort, and hence an increased yield or capacity of treatment. The number of retorts mounted in parallel, may be considerably reduced, which is a great advantage for the obtainment of a regular pperation because the parallel arrangement causes irregularities in the proper distribution, which tend to be amplified when the apparatus becomes since, as the speed of circulation decreases, the temperature of the gas tends affording access 'to rise to the tem ratureof the heating'un'it structure, and t is increases the due to the cracking efiect.

Obviously, the arrangement of the tretorts is not limited to that shown in Figure '1. Thus, the combination of two adjacent rows of oblique retorts inversely inclined (Fig. 4) will ermit, for a givenhe'ight and only a doub e width, to place several series of retortsinparallel. v 1

If it is desired to stir the vapours between two successive retorts, a baflie or deflector with restricted passages in each elbow :may

be provided. The ad acent retonts may also be connected by a con ling member which, instead of being horizontal as shown in Figure 4, will cause the vapour to :follow a short upward path. reduces the vertical paratus. V

The expansion and coolin unit comprises a set of tubes, the cooling uid bein' circulated through said tubes, which'may structed in any suitable manner; for instance, the sets of tubes may be similarto those employed in the tubular boilers of the Grille, Babcock, Field and other types.

By way of example, shown in Figure 1' comprises a set of oblique Field tubes, each consisting of an :outer tube 11 connected the coolin fluid, I nected to t e inlet collector 14. for the admission of the cooling fluid. The cooling fluid This arrangement also bulk-or height of the apwhich circulates through the tubes should I conthe expansion unit I to the outlet collector 12 for and an inner tube '13, coni have an intense cooling effect, .in order that 4 the surface of the tubes might be reduced, as much as possible, and the cooling action made as abrupt as possible. I

The cooling fluid may consist of water, which is raised to the boiling'point when passing through the tubes, or of any. other fluid, optionally under pressure.

The lower part of the expansion unit preferably consists of aregulatin chamber 15 provided with the return cont uit 16 for returning to the boiler the heavy'produ'cts which. have not been depolymerized. A conduit '17; connects chamber '15 with the top of the succeeding expansion unit or with the fract'iona wire gauze or screen 18 is adapted to prevent all obstruction of conduit .17 by the metallic scale or other catalyst pontained "in the cooling andexpanding unit.

' At the upper part is provided a cover19, to the interior of the appara tus., It is also observed that the tubes are readily accessible from the side. 19a denotes a conduit for, the optional intake of return materials from the following apparatus, or of raw hydrocarbon oils not been removed.

The expansion unit above described aflords a quick and abrupt cooling of the whole 111855 from which "petrol has of vapours in the resence of the catalyst, to

bine with the unstable substances delivered from the retorts. Furthermore, the cooling members or tubes occupy but a small space, thus leaving the maximum volume for the hydrocarbon vapours.

The condensation of the heavy substances disengages a suflicient amount -of heat, to maintain the tem rature substantiall constant within the igester chamber 15, or extom of the usual fractioning tower (not' shown).

Fig. 2 shows a modification of thdexpan. sion and coolin unit in which the\Field tubes are vertica the regulating chamber being arranged at the top. The tubes open at the upper end into an inlet collector 21, supplied with cold or hot water from a pi 22.

The steam produced is dischar d through a conduit 23, and may be utilize in a prime mover or as a heating medium. The hydrocarbon vapours enter through the conduit 24 and circulate downwardly around the tubes 20. Baflles 25 are preferably provided to slow up the circulation of the vapours and to keep them longer in contact wit the tubes. The light vapours escape at the top at 26, while the27condensetl hydrocarbons are collected at Obviously, the gas may enter at the side of the apparatus. 'The cooling unit may also be filled with metal scale or other catalyst.

Fig. 3 shows another modification of the cooling and expandingunit, in which the set of tubes 28 is of the Grille type. The tubes are connected to aninlet collector 29, supplied for instance with cold water, and to an outlet collector 30 for the discharge of hot water. The vapours enter at 31 and are discharged at the bottom at 32, so that an inspection cover 33 may be provided at the top.

It is obvious that the vapours may also be circulated upwardly.

The gases which are not condensed in the plant, comprising the fractioning and scrub hing tower or towers, may he returned to any suitable part of the plant such as to the vaporizer, heating unit or cooling and ex--' Y panding unit, where-they are again subjected to one or several steps of the cycle of opera'- j In particular, when the gasescontain a large proportion of methane, said gases, preferably after they are purified, may be circulated in a known manner over suitable substances at high temperature, so as to convert the methane into a mixture of hydrogen and. non-satured hydrocarbons' The gases thus treated are a sin introduced'into the cycle, whereby the ydrogen and non-saturated hydrocarbons will combine with the vapours under treatment so as to finally increase the proportion of light liquid hydrocarbons similar to'petrol.

Having now described my invention what I claim as new and desire to secure by Letters Patent'is:

1. In an apparatus for the depolymerization of high boiling point hydrocarbon vapors, a heating unit comprising a hollow heat insulating frame, a set of superimposed 'inclined retorts mounted in said frame and means for sup- 1 the material to e heated, dischar e means connected to the.

connected together in series, lying the lower retort with uppermost retort or the escape of said mav.terial, means for supplying a heating medium into the hollow part of said frame, at the top thereof, an escape aperture for said medium at the,botto1n of the frame, deflecting means within said frame to oblige said heating medium to flow substantially along each in ividual retort, an unheated and heat insulating catalytic chamber provided at the top of said frame and interposed between the uppermost retort and the discharge means and in which the heavier vapors are condensed and means for the removal there from of the condensate.

, 2.. In an apparatus for the depolymerization of high b vapors, a heatin heat insulating rame, a plurality o superimposed retorts inclined and serially conoiling point hydrocarbon unit comprising a hollow nected together so as to form an ascending channel for the material to be heated, means for sup lying the loweraretort with said materia discharge means connected to the uppermost retort or the escape of said material, baflies extending in the hollow part of the apparatus .and defining together and with the walls of the frame a plurality of' chambers serially connected end to end and each of which encloses one retort in-wch a manner that an annular channel is provided all round'the retort and along the same bedium into the upper one of said chambers, and an escape aperture for said medium from the lowerone 0 said chambers.

p 12s tween thechamber walls and the wall of said .retort,"means for supplying a heating me- 3. In an a paratns as claimed in claim 2, retorts having a. flat and substantially rectangular cross-section with the great dimension vertically disFosed.

' In testimony whereo I have signed my name to this specification.

JEAN MERCIER. 

